October, '17] REVIEWS 507 



few months should be devoted to learning the needs for both and 

 making plans to secure the effective distribution of machinery and 

 insecticides. One is well nigh useless without the other. This dis- 

 tribution must be followed by effective operation or the work counts 

 for little. 



Data at hand should be made available to indicate the safest rota- 

 tions or desirable modifications in cropping in order to prevent insect 

 injury. Every entomologist knows the risk incurred by planting 

 corn or potatoes on land badly infested by young white grubs, the 

 sowing of wheat early enough to permit infestation by Hessian fly, etc. 

 Such precautions involve little or no additional labor. Self-interest, 

 if not concern for the national welfare, should and probably will lead 

 most farmers to observe these common-sense precautions and it is 

 for the economic entomologist to see that he can not plead ignorance 

 of the matter — it would be even better if growers had the stimulus of 

 nearby demonstrations. 



Reviews 



School Entomology, An Elementary Textbook of Entomology for 

 Secondary Schools and Agricultural Short Courses, by E. D wight 

 Sanderson and L. M. Peairs. John Wiley & Sons, New York, 

 1917. Pp. 356, figs. 233. Price, $1.50. 



We have in this work an excellent discussion of the systematic and economic phases 

 of entomology admirably adapted to the needs of agricultural and secondary students 

 in particular. There is enough of structure and taxonomy to give the student a good 

 idea of insect hfe and yet this aspect is not allowed to obscure the more practical 

 part II. It has been said, and truly, that all entomology is economic and yet there 

 are some works on economic entomology that run largely to the systematic and vice 

 versa. This book is admirably proportioned. The keys are sufficient for consider- 

 able taxonomic work. The student will find material assistance in the series of illus- 

 trations showing types of the more important groups of insects. The economic part 

 is Umited to discussions of the more destructive pests. The value of the book is 

 greatly increased by the short list of the more important recent contributions to 

 insect literature, thus making further study easy. The authors have produced a 

 very meritorious work which wiU be greatly appreciated by teachers and students. 

 (Advt.) 



